This is the list of questions most commonly asked by the newcomers to the Linux wireless networking land, along with the answers.

Q: Is my XXX model device supported?

A: Forget about XXX, what really matters is PCI or USB (depending on the bus your device uses) ID pair: VID:PID. So to find out if your device is supported, use lspci -nn or lsusb to learn the ID pair.

Then navigate to Google and type the request in the form "VID PID" site:cateee.net/lkddb/ (e.g. "14e4 170c" site:cateee.net/lkddb/). If there is a hit, this will allow you to learn which driver to use for your device. If there is no, the device is most probably unsupported (though if you are really sure some driver should support it, you can try modifying the driver source to add the ID, or use newid sysfs node for USB devices).

Q: I still have problems using my device

A: Follow this checklist:

  1. Install the latest stable backports

  2. Navigate to the driver page corresponding to your device to learn about limitations or additional requirements.

  3. Read dmesg output carefully, paying extra attention to firmware-related messages.

  4. Use rfkill list to see if there are any rfkill-related issues, there must be no kind of blocks present for you wireless interface. Sometimes there is a mechanical switch that needs toggling for leveraging "hard" block.

  5. Try using iw and wpa_supplicant directly, without NetworkManager or similar tools.

  6. Install bleeding edge backports to see if the problem is reproducibile with that. In any case you might want to report the issue as stable releases should have all known bugs fixed.

Q: iwconfig tells me bla-bla-bla error

A: Please use iw and wpa_supplicant instead. iwconfig is using deprecated way of communication with the kernel which is supported only in compatibility mode, has some limitations and might be removed altogether at some point.

Q: iwconfig wlan0 mode master does not work

A: Use hostapd and a driver supporting AP mode for running in master/AP mode. Setting a device into master mode with iwconfig is not supported by modern drivers.

Q: Why can't i use channel X, i did iw reg set NN but it is still unavailable

A: Every card sold was certified to work in a particular regulatory environment (that being set of channels, maximum allowed power, other special flags etc). On Intel cards these restrictions are enforced by firmware, Atheros's equipment has regdomain code in EEPROM which is read on startup by the driver and then (if it's not "world" regdomain) CRDA is contacted to get a set of regulatory requirements.

Q: I've installed some driver from somewhere, now i have ra0 interface etc...

A: If you are using drivers directly from vendor (and not from upstream Linux or compat-wireless) please ask your vendor for support through its support channels, linux-wireless has nothing to do with that.